Quick Spins – February 2, 2008 Edited by James Huang Got Tech? Send press releases, news, and tech questions to the Cyclingnews tech-heads. Rotor S1 stem Rotor expands into the lightweight component market Rotor's DTT bolts make it all possible. The two-bolt faceplate Red or black: your choice. Photo ©: Rotor Rotor made a name for itself with its eponymous cranks and elliptical referenceQ-Rings but lessons learned in the development of its latest Ágilis crankset, namely its unique Double Thread Technology (DTT) hardware, have steered the company into the lightweight components direction. The DTT bolts resemble basic set screws except that each end uses a different thread pitch. Mating parts are essentially pulled together by their respective threads so there's no head on the bolt and less localized clamp pressure so the parts no longer have to be reinforced there. Once assembled, the DTT bolt also acts as a sort of reinforcement rod (think rebar). According to Rotor, its DTT concept reduces overall component weight, improves stiffness and reliability, and even increases clamping torque. One thing is for certain: our Rotor S1 sample stem is seriously light, weighing just 112g in a 120mm x ±7.5° x 31.8mm size. Moreover, its oversized dimensions also impart a notably more rigid feel than most other comparably lightweight stems we've tested in recent memory and the DTT hardware design makes for a decidedly sleek and graceful appearance (check out the faceplate). Overall quality was excellent, from the precision of the machining work and laser etching to the durability of the anodized finish. Inexperienced mechanics will want to take some care during installation, though, as using the DTT system isn't entirely intuitive. The concept does seem to work as advertised but there's a definite procedure to the operation and it's relatively easy to do incorrectly. The aggressive extension machining also doesn't leave much surface area to grab on to slippery carbon handlebars so be sure to have some friction paste on hand (we now use the stuff on all carbon clamp surfaces anyway). Otherwise, Rotor's new S1 has emerged as one of our favorite ultralight stems, bearing all of its intended lightweight goodness with little compromise that we can find. A slightly beefier SX model with a four-bolt faceplate is just about ready, too, and Rotor will also launch a lightweight S1 seatpost with DTT technology in the near future. Considering the S1 stem marks Rotor's first foray outside of cranks and chainrings, we'd say there are likely more good things to come. Price: US$174 Weight: 112g (120mm extension) Pros: Ultralight weight, surprisingly rigid feel, superb quality Cons: DTT system requires care in installation, friction paste strongly recommended for handlebar clamp on carbon bars Cyclingnews rating: More info: www.rotorbike.com Photography For a thumbnail gallery of these images, click here Images by James Huang/Cyclingnews.com Rotor expands into the lightweight component market with its new S1 stem. The S1's beefy extension makes for a stiff feel. Rotor's DTT bolts make it all possible. The two-bolt faceplate is particularly sleek since it doesn't have to be reinforced against the pressure of conventional bolt heads. DTT bolts are also used for the steerer clamp. Images by Rotor Red or black: your choice.